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Biomedical subjects

C J Richards

Publications and source records attributed to C J Richards.

62 records · Page 4Linked to original sources
PubMed1978

Effects of indomethacin on the vascular abnormalities of Bartter's syndrome.

We examined the hypothesis that the vascular abnormalities of Bartter's syndrome are due to excess production of prostaglandin. Balance studies and vascular reactivity studies were performed before and after indomethacin (200 mg/day) in a patient with well-documented Bartter's syndrome. During indomethacin, potassium balance became positive, serum potassium rose from 2.1--3 mEq/1 in the absence of potassium supplementation, plasma renin activity decreased from 55--3.2 ng/day and peripheral plasma PGA-like activity fell from 1460 +/- 220 to 456 +/- 71 pg/ml. Before indomethacin, forearm vasoconstrictor responses to brachial arterial infusions of angiotensin II, norepinephrine and to neurogenic reflex stimulation elicited by lower body suction were greatly depressed compared to those of normal subjects. During indomethacin these responses were restored to normal. The dose of intravenous angiotensin II required to increase diastolic blood pressure 20 mm Hg decreased from 160--30 ng/kg/min. These data support the hypothesis that the vascular insensitivity to exogenous angiotensin II, norepinephrine and to neurogenic reflex stimulation observed in this patient with Bartter's syndrome is due to excess prostaglandin. Moreover, stimulation of the renin-angiotensin-aldosterone system in this syndrome appears to be a compensatory adaptation to excess prostaglandin production.

Adult↗
PubMed1977

Acetate-free hemodialysis with a sorbent regenerative system.

We conclude from this study that acetate-free, bicarbonate hemodialysis is well suited to the sorbent regenerative system. It can be performed safely and gives postdialysis patient values similar to standard dialysis. Long-term trials are presently being conducted at our institution. With modification of the cartridge pH by the manufacturer, it should prove simple and practical.

Acid-Base Imbalance↗
PubMed1977

Glucose tolerance tests and their insulin and growth hormone responses in hemodialysis patients: are they reproducible?

The concept that carbohydrate intolerance improves after hemodialysis has been challenged. Critical to this issue is the reproducibility of GTT in a dialysis population. Thirty-nine oral or i.v. GTT were performed on ten stable hemodialysis patients at weekly intervals for three weeks. Blood glucose was determined by both oxygen consumption rate during glucose oxidation and the ferricyanide method. The coefficient of variation of blood glucose ratios (Glucose at time X/Fasting glucose) by glucose oxidase varied considerably. With the i.v. GTT the coefficients of variation at 90 and 120 minutes were 27.9 and 36.8 percent in one patient but below 15 percent at 60, 90, and 120 minutes in the other four patients. Three of the five patients who received oral GTT displayed coefficients of variation greater than 20 percent at one or more sampling times. The coefficients of variation of the growth hormone ratio (Growth hormone at time X/Fasting growth hormone) during i.v. and oral GTT ranged from 2.1 to 83.6 percent. Coefficients of variation of insulinogenic indexes ranged from 16.3 to 59.3 percent. In summary, large variations in glucose, growth hormone and insulin occur during both oral and i.v. GTT when repeated on a weekly basis in stable hemodialysis patients.

Administration, Oral↗
PubMed1975

Zinc metabolism in aminonucleoside-induced nephrosis.

Nephrosis was induced in Sprague-Dawley rats in two separate studies by injections of aminonucleoside with sacrifice of animals on days 20 and 54, respectively. Experimental animals in both studies showed the typical findings of nephrosis, i.e., hypoalbuminemia, hypercholesterolemia, and proteinuria. Biochemical findings included hypozincemia and hyperzincuria. A significant correlation between hypozincemia and hypoalbuminemia was noted in the short-term study. Proteinuria occurred on the 10th day in the short-term study and the 15th day in the long-term study and increased quantitatively over the remaining days. The hyperzincuria and proteinuria correlated significantly in the long-term study. Measurements of tissue zinc revealed no change in testes and kidney in the short-term study. Kidney and muscle zinc were increased, testicular zinc was unchanged and femur zinc was decreased in the long-term study. Our conclusions are that in the aminonucleoside induced nephrosis of the rat: 1) hypozincemia occurs probably as a result of hypoalbuminemia, 2) the hyperzincuria is likely due to proteinuria and 3) zinc deficiency is not observed in nephrotic rats who receive ample zinc in their diet and who are observed up to 6 weeks.

Animals↗
PubMedDate not supplied

Transient post-partum thyroid dysfunction and postnatal depression.

In the course of a population study of thyroid dysfunction in pregnancy and the post-partum period, 65 women, considered to be antibody-positive (microsomal and thyroglobulin), and 82 antibody-negative women were assessed for postnatal depression at 6-8 weeks post partum. The women were also assessed for the development of post-partum thyroid dysfunction. Of the 147 women, 22 met DSM-III criteria for major depression. The presence of autoantibodies showed little association with depressed mood but there was a minor association of postnatal depression with actual thyroid dysfunction in that incidence of the latter condition was higher in depressed women (Raskin scale P less than 0.01; Edinburgh scale P less than 0.05; Montgomery-Asberg scale P less than 0.1). Three of eight mothers with thyroid dysfunction had major depression and were depressed on all three scales.

Adult↗